ok, you may very well be correct, and I don't know how many options may be expiring...however, the reasons i think you might do it would be these:

Assuming 350,000 options,

1. total daily volume is so low lately, 26-75k...that you would have to put in 20k of shares a day or less to not raise the ask significantly; (at 70k last daily volume would take 5 full days to fill without possibly raising the ask......doubtful

2. convenience...especially if your not worried about the upside..and hey--you can use the tax loss!